I just bought a used 2007 MB E-350 two weeks ago and there is posted message in the instrument panel saying Schedule F due in 4023 miles. Also I heard conflicting information from the MB Dealerships and the MB mechanics I knew regarding the transmission flushing maintenance of my vehicle. I was told the transmission fluid should be lifetime while the dealership said that I have to wash the fluid every 40,000 miles. I need clarification on this matter. Thanks.